Hello, I am very new to BPMN. We are currently using Drools 5.3 version. I face the below error when i run the project. Also am trying to understand the running of Call Activity. Anyways a flow does begin running and then it gives the following error java.lang.NoSuchFieldError: session at org.jbpm.process.instance.impl.MVELReturnValueEvaluator.evaluate(MVELReturnValueEvaluator.java:91) at org.jbpm.process.instance.impl.ReturnValueConstraintEvaluator.evaluate(ReturnValueConstraintEvaluator.java:128) at org.jbpm.workflow.instance.node.SplitInstance.internalTrigger(SplitInstance.java:72) at org.jbpm.workflow.instance.impl.NodeInstanceImpl.trigger(NodeInstanceImpl.java:124) at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerNodeInstance(NodeInstanceImpl.java:205) at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerCompleted(NodeInstanceImpl.java:164) at org.jbpm.workflow.instance.node.ActionNodeInstance.triggerCompleted(ActionNodeInstance.java:55) at org.jbpm.workflow.instance.node.ActionNodeInstance.internalTrigger(ActionNodeInstance.java:51) at org.jbpm.workflow.instance.impl.NodeInstanceImpl.trigger(NodeInstanceImpl.java:124) Not sure i understood this error. Would appreciate if some help could be provided with what the error meant exactly. Regards, starfish. -- View this message in context: http://drools.46999.n3.nabble.com/BPMN2-Question-tp4023888.html Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users